Flea markets are a great place to wander around
and kill a morning. When I saw a
1960's industrial grade tool post grinder with accessories, in
a wooden case, for the princely
sum of $100 AUS I jumped at it - an absolute bargain.

For the
money I got an Australian made Waldown
unit - very similar to the American Dumore of the same vintage.

It came with a motley assortment
of vintage cup and
valve grinding/refacing stones, an
additional
quill with long tapered spindle for internal
grinding and buffing (often missing from these kits), a full set of
unused internal grind stones, and a spare drive
belt.

The unit hadn't been resprayed or doctored up, and
was in original as used condition.

The motor spins at 12,000 RPM and the
spindle speed can be
geared up or
down using various diameter pulleys as required.

The 1/2" tool post mounting hole was not designed
for
Chinese engineering, so the 10mm bolt and stepped
flange on my
top slide presented a problem.

I machined up an adapter plate, but it was not
ideal, as the centre line axis was about 10 mm higher than the lathe.

I used it
like this until I had time to correct the issue. The options
were
to heavily machine the grinder mount (which I didn't want to do) or to
make up a specific mount for the cross slide (which I did).

While I
was at it, I incorporated it into a "super"
toolpost and overcame some topslide flex issues at the same time.

The
downside is that you need the topslide to grind sharp tapers (eg.
centres), so the heavy base, while good for most jobs, has
it's
limitations.

Below are
two shots of the new mount before I polished out the machine marks from
the fly cutter. Using the toolpost grinder for the same
job, those marks would be non existant as there is no
shock loading from the cutter. A great machine.

This "super" toolpost is also super rigid.

Fine adjustments can still be done using the micro
adjuster on the carriage stop.

Other photos on this page show the grinder mounted
on the original spacer (which got the unit up and running quickly).

Left side below.

And the
right side - showing the two
speed pulley on the motor. The larger pulley is only used for
the
internal quill, which requires extreme rotation speeds for the very
small stones.

The
grinder mounts rigidly, and is a
solid and well made unit.

Here's a photo of it with the internal quill mounted, to centre my
external chuck jaws.

Close
examination revealed the spindle bearings in both quills were
bone dry, and one bearing was shot. CBC Australia
Pty Ltd sourced replacement bearings for me - NSK
EN12. These are a type of magneto bearing.

The shaft for the internal quill was also in back to front.

Lubrication

When repacking and fitting the bearings I noticed what appeared to be
an oil port in the top of each quill. Not being sure if the
bearings ran in grease or an oil bath, I Emailed Brobo Waldown
(Aust) Pty Ltd for clarification.

I was pleasantly surprised to receive a user manual for
Waldown Tool Post grinders through the post - gratis. What a
great company. Thank you Brobo Waldown.

The manual revealed that the bearings are greased at
assembly, then
oil
is then added daily through the oil port for long term
lubrication. The oil bath cuts drag, and lowers the
temperature of the bearings enormously.

The screw head for the oil port can be seen below
near the
centre of the internal quill.

The dual pin wrench is used to preload the bearing
retainers to remove endplay. Tension the grind
stone end adjuster with the unit running until revs start to
drop,
then back it off to full speed, and leave it there. If
necessary pack the bearing to position with paper shims.

The wrench was missing from the kit, so I made one.
I cleaned
and greased the motor armature bearings while I was at it.
The
brushes
and commutator looked quite OK. I also blew the
accumulated
dirt and grindings out of the field windings and motor body so
that everything was as good as new.